JPH07165109A - Body structure for vehicle - Google Patents

Abstract

PURPOSE:To provide a body structure wherein energy absorbing efficiency by a metallic cylindrical frame member protruded in a direction toward outside from a cabin is sharply increased. CONSTITUTION:Carbon fiber reinforced resin 15, having a carbon fiber 15a arrayed in a direction nearly parallel to the axis direction of a member, and a carbon fiber 15b, crossing this carbon fiber 15a to be arrayed in a direction nearly orthogonal to the axis direction of the member, is fitted to the wall surface of the metallic side member. Consequently, high withstand-load performance at collision initial period can be displayed by arranging the carbon fiber 15a and moreover, stable collapse performance can be displayed by arranging the carbon fiber 15b in the metallic side member to obtain high ride-down efficiency when collision happens.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body structure capable of absorbing impact energy when an impact is applied to the vehicle body from the outside.

[0002]

2. Description of the Related Art In automobiles, a structure for protecting an occupant from an impact at the time of a collision is provided over many surfaces. As shown in FIG. 9, in a vehicle body 1 of an automobile, a frame portion protruding from a passenger compartment 2 in a front-rear direction, for example, tubular side members 3 and 3 on both sides in a vehicle width direction (a tubular frame).
The impact energy applied from the front or the rear of the vehicle body 1 at the time of the collision of the automobile is absorbed by utilizing the bump member).

Conventionally, such a side member 3 of the vehicle body 1
Is made of metal such as steel or aluminum, which is referred to as a hat-shaped cross section shown in FIG. 10, and is formed by forming a substantially U-shaped elongated inner panel 4 and a flat outer panel 5 into a closed cross section by spot welding. The tubular member of is used. Further, the side member 3 is set with a plate thickness, a cross-sectional shape, and the like so that when a predetermined value of impact force is applied from the front (or rear) of the vehicle body 1, buckling deformation (collapsed into a bellows) occurs. is there.

Thus, when the vehicle collides with a wall or the like, the buckling deformation of the side member 3 absorbs the collision energy to prevent the portion of the passenger compartment 1 from being deformed as much as possible.

By the way, in order to effectively protect the occupant in the passenger compartment by absorbing the impact, the occupant restraint device such as a seat belt device is operated as soon as possible after the collision,
It is desirable that the occupant is integrated with the vehicle body 1 by restraining the seat, the kinetic energy of the occupant is applied to the deformation of the vehicle body 1, and the kinetic energy of the occupant is absorbed by the deformation of the vehicle body 1 (ride down effect). .

[0006] This is because when a car crashes, the movement of the vehicle body 1 stops from that point, but the occupant is moving (for example, if the occupant restraint system is a seat belt system,
Therefore, if the occupant is restrained early and moved together with the vehicle body 1, the kinetic energy of the occupant is absorbed by the deformation of the vehicle body.

That is, the protection of the occupant is considered to be good by increasing the ratio of absorbing the kinetic energy of the occupant by the deformation of the vehicle body 1 (ride down efficiency: high). To this end, the deceleration of the vehicle body 1 is large immediately after the collision until the occupant is integrated with the vehicle body 1 in order to quickly actuate the occupant restraint device and restrain the occupant quickly. It is said that it should be stable below a certain level or gradually lowered.

That is, the side member 3 is required to have load resistance to withstand a large deceleration and deformability to efficiently absorb kinetic energy. However, as can be seen from the results of the crush test shown in FIGS. 11 and 12, the side member 3 is made of metal, that is, a single steel.
The members constructed from the
The peak value W ₁ is quite low and is not so different from other load peaks.

The buckling pitch P ₁ of the side member 3 when it is buckled (crushed into a bellows shape) is considerably large. That is, the side member 3 absorbs the kinetic energy by the deformation in the out-of-plane direction that occurs when it is crushed in a bellows shape, and absorbs the kinetic energy by the surface pressure due to the contact at the time of the deformation, and therefore buckles The larger the pitch P ₁ is, the lower the energy absorption efficiency of the side member 3 is. Moreover, the single-steel side member 3 is
Since the crushing is unstable, it may be bent and deformed instead of buckling, and the energy absorption capacity is wasted.

[0010]

Therefore, in recent years, instead of a metal side member, Japanese Patent Laid-Open No. 4-5178 has been proposed.
JP-A-4-143173, JP-A-4-15138
As disclosed in Japanese Patent Laid-Open No. 1-58, it has been attempted to adopt a side member made of fiber reinforced plastic to enhance the energy absorption capacity of the side member.

However, this product has a risk of cracking, and the original performance is often not obtained. In addition, in the vehicle body 1 in which metal members are fixed together by welding such as spot welding, the side members made of fiber reinforced plastic, which cannot be welded, require a device for fixing to other metal members. There are difficulties that do not match productivity.

Therefore, the existing metal side member 3
There is a demand for a practical technique for enhancing the energy absorption capacity of the side member 3 by utilizing the above. The present invention has been made in view of such circumstances, and the purpose thereof is to dramatically improve the energy absorption capacity of a metal cylindrical frame member protruding outward from a passenger compartment. (EN) Provided is a vehicle body structure capable of being manufactured.

[0013]

In order to achieve the above-mentioned object, a vehicle body structure according to a first aspect of the present invention has a metal tubular frame member having a wall surface, a tubular member wall surface, and a tubular member. Shape frame
The first reinforcing fibers arranged in a direction substantially parallel to the axial direction of the frame member, and the first reinforcing fibers crossing the first reinforcing fiber and arranged in a direction substantially perpendicular to the axial direction of the tubular frame member. The fiber-reinforced resin layer having the second reinforcing fiber is attached.

In the vehicle body structure according to the second aspect, in order to obtain the highest energy absorption capacity,
It is provided continuously on the wall surface of the tubular member along the circumferential direction.

In the vehicle body structure according to a third aspect of the present invention, in order to ensure a sufficient effect of the fiber reinforced resin layer, the first reinforcing fiber is added in the axial direction of the tubular frame. The second reinforcing fibers are arranged in the range of ± 75 ° with respect to the standard of ± 15 °.

[0016]

According to the vehicle body structure of the present invention, the metallic tubular frame member is provided with the reinforcing fibers arranged in a direction substantially parallel to the axial direction from the tip of the tubular frame member. The peak value of withstand load against the applied impact load is remarkably increased.

As a result, the metallic cylindrical frame member exhibits high rigidity with respect to the same input at the moment of collision, and decelerates the vehicle body with high deceleration. After that, the tubular frame member is crushed by the impact load, and buckling deformation (bellows crushing) occurs.

Since this buckling deformation is restricted by the reinforcing fibers arranged in a direction substantially perpendicular to the tubular frame member, the recessed portion is once pushed out to the outside again during the crushing. The process proceeds while repeating the deformation in the direction and with the peeling of the resin portion.

As a result, the tubular frame member undergoes buckling deformation in a stable and fine shape with a small buckling pitch,
The kinetic energy of the occupant is absorbed. This provides the metal tubular frame member with load bearing capacity to withstand a large deceleration and deformability to efficiently absorb kinetic energy. The energy absorption capacity is dramatically improved.

According to the vehicle body structure of the second aspect, since the above-described operation is stably performed on the entire peripheral wall of the tubular frame member, the metal tubular frame member has high energy.
Can be absorbed. According to the vehicle body structure of the third aspect, the sufficient effect of the fiber-reinforced resin layer can be stably obtained.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in FIGS. Reference numeral 10 in FIG. 1 denotes a side member (cylindrical frame member) to which the present invention is applied and which is bent in a substantially V shape. The side member 10 is a frame portion projecting in the direction from the passenger compartment 2 toward the front of the vehicle body 1, which is the same as that described in the above-mentioned "Prior Art".

The side member 10 is made of a steel or aluminum, which is a hat-shaped cross section, in which an elongated U-shaped inner panel 11 and a flat outer panel 12 are closed by spot welding. A metal tubular member is used. More specifically, the side member 10 is formed by butt welding and connecting the respective member portions 13a and 13b having a hat-shaped cross section, which are divided into front and rear, along the front-rear direction.

The side member 10 has such an outer shape that the cross-sectional area is smaller toward the front end side and the cross-sectional area is larger toward the rear end side (cabin 1 side). Front member portion 13 as shown in FIG.
The plate thickness t _{2 of} the rear member portion 13b is set to be thicker than the plate thickness t _{1 of} a, for example, about twice (t ₁ <t ₂ ). As a result, a portion that absorbs collision energy (a portion that easily collapses into a bellows when receiving a shock from a collision) is formed in the front portion of the side member 10, and a reinforcement member is not separately used on the rear portion side. The part that receives the reaction force (the part that is also difficult to collapse) is formed.

On the entire inner surface of the front member portion 13a,
The reinforcing fiber resin layer 14 is attached. In this reinforcing fiber resin layer 14, as the most preferable reinforcing fiber resin, for example, CFRP15 (carbon fiber reinforced resin: matrix is epoxy resin, reinforced fiber is Made of carbon fiber).

As shown in FIG. 3, for example, this CFRP 15 has a large number of carbon fibers 15a in different directions on the entire peripheral wall of a rectangular resin cylinder 16 having an outer shape corresponding to the inner cavity shape of the member portion 13a. , 15b (first reinforcing fiber, first reinforcing fiber) are embedded and molded.
The resin cylinder 16 is a separate body at the time of molding, but is integrated when completed.

Of these, the carbon fibers 15a are, for example, as shown in FIG. 3, a direction substantially parallel to the direction in which collision energy is input (the direction indicated by the double arrow in FIG. 1),
That is, parallel to the axial direction of the side member 10 (θ = 0
°) is arranged.

The carbon fiber 15b is substantially perpendicular to the direction in which the collision energy is input, that is, the direction perpendicular to the axial direction of the side member 10 intersecting the carbon fiber 15a (θ = 90 °). ) Is arranged.

That is, as shown in FIG. 4, the carbon fibers 15a and 15b are alternately laminated and assembled in a lattice shape. “90 °” in FIG. 4 is carbon fiber 15
The angle at which a and the carbon fiber 15b intersect is shown.

During the process of assembling the side member 10, the square tubular CFRP 15 is bonded to the inner surface of the member portion 13a and the inner surface of the outer panel to be assembled inside the member portion 13a.

With this structure, the reinforcing fiber resin layer 14
Are continuously provided in the circumferential direction of the member portion 13a.
Next, the operation of the side member 10 will be described with reference to the diagram shown in FIG.

For example, it is assumed that a collision occurs at the front part while the automobile is running. Then, the movement of the vehicle body 1 stops from that point. At this time, if the belt of the seat belt device (occupant restraint device) is hung on the upper body of the occupant seated on the seat, the occupant will move forward by the amount of deflection of the belt. And

Here, the member portion 13a of each side member 10, 10 (front side) to which the impact energy of collision is input is a carbon fiber arranged in a direction parallel to the axial direction of the side member 10. by 15a, the load bearing pin against the impact load applied from the tip - click value W ₂ is enhanced remarkably.

This means that the member portion 13a of the side frame 10 exhibits high rigidity at the moment of collision and decelerates the vehicle body 1 with high deceleration. Due to this high deceleration,
The occupant restraint function of the seat belt device raises the occupant as quickly as possible and restrains the occupant moving forward in the seat as quickly as possible.

As a result, immediately after the collision, the occupant is integrated with the vehicle body 1 as soon as possible. Subsequently, the member portion 13a of the side frame 10 is crushed by the impact load, and buckling deformation (bellows-like crushing) occurs.

Here, the member portion 13a which absorbs the collision energy is restricted from being deformed in the out-of-plane direction by the carbon fiber 15b. For this reason, the buckling deformation of the member-portion 13a proceeds while repeating the deformation that the recessed portion is pushed outward again once during the crushing, and with the peeling of the resin layer of the CFRP 15.

As a result, the member portion 13a undergoes buckling deformation in a stable and fine shape with a small buckling pitch P ₂ as shown in the result of the crush test shown in FIG. At this time, the kinetic energy of the occupant on the vehicle body 1 is absorbed by the deformation of the member portion 13a in the out-of-plane direction and the surface pressure caused by the contact during the deformation.

The buckling deformation of the member portion 13a is
Since it occurs stably with a small buckling pitch P ₂ , the kinetic energy of the occupant is absorbed with high energy absorption efficiency.

As a result, the occupant is protected from the impact of a collision with a high ride-down efficiency. Therefore, the metal side member 10 has a reinforcing fiber 15 in a predetermined direction.
By providing the CFRP 15 in which a and 15b are arranged, the load bearing capacity to withstand a large deceleration and the kinetic energy
It can be seen that both the deformation performance that efficiently absorbs

As a result of the crush test, the side member 10 has the occupant protection and kinetic energy shown in FIG.
The waveform of the deceleration of the vehicle body which is most suitable for absorbing the carbon fiber, that is, the carbon fiber 15a realizes a high load resistance.
The stable crush load was realized by 5b.

Therefore, the energy absorbing ability of the side member 10 extending forward from the passenger compartment 2 can be dramatically improved. In addition, the metal side member 10 exhibits the highest energy absorption capacity by the CFRP 10 being continuously provided in the circumferential direction of the side member 10 (the above-described action is stable in the entire peripheral wall of the member portion 13a. Because it will be done).

As a result, it is possible to provide the vehicle body 1 which is excellent in occupant protection. Particularly, the performance of the side member 10 is within a range of ± 15 ° with respect to the direction in which the carbon fiber 15a is input with an impact, that is, the angle parallel to the axial direction of the side member 10, and the carbon is also the same. Fiber 15b is ± 75 °
When it was arranged in the above range, it stably exhibited when laminated, and in other cases, the effect of CFRP15 was not observed.

Specifically, the carbon fiber 15a is ± 15 with respect to the angle parallel to the axial direction of the side member 10.
Arrange in the range of °, and also carbon fiber 15b ± 75
As a result of a crush test of the side member 10 to which the CFRPs 15 arranged in the range of ° are attached, as shown in FIG. 7, a high load bearing peak due to the carbon fiber 15a as described above is obtained.
Although it was confirmed that the curb value P ₂ and the stable crush load due to the carbon fiber 15b, combinations exceeding the same range,
For example, in the side member 10 to which the CFRP 15 in which both the carbon fiber 15a and the carbon fiber 15b are arranged in a range of ± 75 ° is attached, a high load-bearing peak value P ₂ is generated as shown in FIG. It wasn't.

That is, the carbon fibers 15a are arranged substantially parallel to the axial direction of the side member 10, and the carbon fibers 1
It is understood that the desired performance can be obtained as long as 5b is arranged in a direction substantially perpendicular to the coaxial center direction.

Further, also when the CERP 15 was simply placed inside the side member 10 without being bonded to the metal side member 10, the same crush test was conducted.
At this time, there were many cases where the CERP 15 was cracked and the original performance did not occur. In other words, it can be seen that attachment is also a requirement for achieving the purpose.

Although the CFRP is attached to the inner surface of the metal side member in the embodiment, the same effect can be obtained by attaching the CFRP to the outer surface. In addition, in one example, an example in which CFRP using carbon fiber is used as the reinforcing fiber is given, but the present invention is not limited to this, and a fiber-reinforced resin using another reinforcing fiber may be used.

Furthermore, in one embodiment, the present invention is applied to the side member on the front side of the vehicle body, but the present invention is not limited to this, and the present invention is applied to the side member on the rear side of the vehicle body. The present invention may be applied to a vehicle body having a metal member protruding in the width direction of the passenger compartment. That is, the object can be achieved by applying the present invention to a tubular frame member made of metal and protruding outward from the passenger compartment.

[0047]

As described above, according to the first aspect of the present invention, the metal tubular frame member protruding from the passenger compartment in the outward direction is provided with a high ridedown efficiency at the initial stage of collision. It is possible to provide high load bearing performance and stable crushing performance thereafter.

As a result, the energy absorption capacity of the metallic cylindrical frame member can be dramatically increased. As a result, it is possible to realize a vehicle body having a high ridedown efficiency and excellent occupant protection.

According to the second aspect of the invention, in addition to the effect of the first aspect, it is possible to give the highest energy absorbing ability in the metallic cylindrical frame member. According to the invention of claim 3, in addition to the effects of claims 1 and 2, a sufficient effect of the fiber reinforced resin layer can be secured.

[Brief description of drawings]

FIG. 1 is a perspective view showing a metal side member with CFRP, which is a main part of one embodiment of the present invention.

FIG. 2 is a sectional view of a “portion that absorbs collision energy” of the side member taken along the line AA in FIG.

FIG. 3 is a perspective view for explaining the structure of a CFRP attached to the same portion.

FIG. 4 is a perspective view for explaining the arrangement of carbon fibers of CFRP.

FIG. 5 is a view for explaining how the metal side member with CFRP is crushed.

FIG. 6 is a diagram showing a waveform of a vehicle body deceleration when the side member is crushed.

FIG. 7 is a diagram showing a waveform of a vehicle body deceleration when carbon fibers are arranged in an angle range of “± 15 °” and “± 75 °” with reference to the axial direction of the side member.

FIG. 8 is a diagram showing a waveform of a vehicle body deceleration when carbon fiber is laminated in a combination outside the angle range.

9 (a) and 9 (b) are a front view and a side view showing a vehicle body of an automobile together with a metal side member protruding in a direction outward from a passenger compartment.

FIG. 10 is a perspective view showing in detail a metal side member on the front side.

FIG. 11 is a view for explaining how the side member made of the same metal is crushed.

FIG. 12 is a diagram showing a waveform of a vehicle body deceleration when the side member is crushed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Side member (cylindrical frame member made of metal) 13a ... Member part (part which absorbs impact) 14 ... Reinforcing fiber resin layer 15 ... CFRP (carbon fiber reinforced resin) 15a ... Carbon fiber (first) 15b ... Carbon fiber (second reinforcing fiber)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B62D 29/04 Z // B29K 105: 10 B29L 31:30

Claims (3)

[Claims] 1. A passenger compartment, and a tubular frame member made of metal, which protrudes outward from the passenger compartment, wherein the tubular frame member has a shocking force applied from a tip end side. A vehicle body structure capable of buckling deformation with respect to a load, comprising: a first reinforcing fiber arranged on a wall surface of the tubular member in a direction substantially parallel to an axial direction of the tubular frame member. A fiber reinforced resin layer having a second reinforcing fiber which intersects with the first reinforcing fiber and is arranged in a direction substantially perpendicular to the axial direction of the tubular frame member is attached. A vehicle body structure characterized by the above. 2. The fiber-reinforced resin layer is the tubular frame.
The vehicle body structure of the vehicle according to claim 1, wherein the vehicle body structure is arranged continuously on the wall surface of the frame member along the circumferential direction. 3. In the fiber-reinforced resin layer, the first reinforcing fibers are ± 15 ° with respect to the axial center direction of the tubular frame.
The second reinforcing fibers are also arranged within the range of ± 75 °
The vehicle body structure for a vehicle according to claim 1 or 2, wherein the vehicle body structure is provided in the range of.